Spark-plug.



H. W. JONES.

SPARK PLUG. APPLICATION FILED DEO.10, 1909.

Patented Apr. 4, 1911.

/lz niente/o [Tommi exceedingly thin metal and the insulating HENEBY WILBUR JONES, OIF4 CEDAR RAPIDS, IOWA.

SPARK-PLUG.

Specification of Letters Patent.

Patented Apr. 4, 1911.

'Application led December' 10, 1909. Serial No. 532,486.

To all whom 'it may concern:

Be, it known 'that I, HENERY WiLnUn JONES, a citizen ofthe United States, residing at Cedar Rapids, in the county of Linn and State of Iowa, have invented new 'and useful Improvements in Spark-Plugs, of which the following isa specification.

Thepresent invention' is designed to provide a spark plug for internal combustion engines, 'which maybe cheaply constructed andis both durable and free from subjecting' the user to electric shocks in the operation of the engine when bringing the hand in contact with the plug and when placing the-conducting wirein place or removing the same from the plug or when performing any-work requirlng contact of the hand with the plug. v

The invention also' contemplates a structure enablinl the metal parts of the plug to be forme fof cold rolled steel or other body to be of comparatively large proportions, so as to insure stability and effective insulation, whereby the annoyance experllenced from receiving shocks of spark plugs as generally constructed is wholly or in part overcome.

The invention consists of the novel features, details of construction and combination of parts, hich hereinafter will be more particularly the accompanying drawing, in the appended claims. I

Referring to the drawing, forming a part of the specification, Figure 1 is a vertical central section of a spark plug embodying the invention, showing the conducting wire in position. Fig. 2 is a horizontal section on the line 2-2 of Fig. 1. Fig. 3 is a horizontal section on the lin'e 3-3 of Fig. 1.

and pointed out Fig. 4 is a sectional View of the insulation and 'end apllied to the terminal of a wire conductor. ig. 5 isl a horizontal section on the line. 5-5 of Fig. 4. Fig. 6 is a plan view of the blank from which the metal end a plied to the conducting wire and insula- Fio. 7

tion illustrated in Fig. 4 is formed. is a detail view of the socket secured wittliin the insulating body for reception of the' conducting wire.

.Gorrespondlng and like parts are re ferred to in the following` description, and

indicated in 'all the views of the drawing, by the same reference characters.

set forth, illustrated in manner.

The siark pug comprisesy an .insulating body lyorme of any dielectric or refractory material, such as porcelain, hard rubber, earthenware and the like. The body 1 is'comparatvely large so as to provide ample insulation 4to prevent the unpleasant shock generally experienced by the hand coming in contact with the usual s rk plug. The inner or lower end of the msulating body is made slender, as shown at 2, so as to become heated and' consume soot or carbon that may deposit thereon. An annular en: largement 3 is rovided midway the ends of the body l-an forms a supporting shoulder and an abutting shoulder whereby the insulating body is retained within the shell or casing. The upper `or outer end of the body 1 has an opening 4, which is contracted at its lower end to receive ay socket 5, which is retained in place by a fastening 6. The socket 5 comprises spring portions, which grip opposite sides of the terminal of the wi-re 7 which leads from a current genera-` tor. The opening 4 admits of the terminal of the wire 7 being introduced into the socket 5 without' subjecting the operator to a shock, since the projecting part of the body 1 prevents the Short circuiting of the current through the'hand. The inner or lower end of the body '1 is provided with an opening to receive the sparking terminal 8, which is usually a platinum point and connected to a nut 9 with which the fastening 6 also makes screw thread connection. The

construction is such as to admitl of ready adjustment or replacement of the sparking terminal.

The insulating body 1 is secured within .a shell or casing 10,l the upper portion of which is enlarged and the lower portion of which terminates in a threaded shank to be tted to the engine body in the well known An inner shoulder 11 is provided near the upper end of the shell 10 and receives the annular enlargement 3 of the body l1. A packing 12 is spaced upon the annular enlargement 3 and is confined b means of a gland 13, which is threaded 1nto the upper portion'of the shell. The packing12 may be of any' material and consists of a slender ring covered b asbestos. The shell or casing 10 is forme of sheet metal compressed or rolled into the desired shape,steel being vpreferred and the same being cold rolled with the result that the shell is exincloses the projecting end of the wire. The

upper edge of the blank is toothed, as indicated at 17, and is adapted to be bent inward solas to enter the insulation, as indlcated most clearly in Fig. 4. A tongue 18. lis provided at one end of the blank and an' opening 19 at the opposite end osaid blank. lVhen the blank is bent around the insulated portion of the Wire it is made secure'by the '1tceth'1'7 entering theinlsulation and by the tongue 18, which' is passed through the openiug 19 and clenched, as indicated most lclearly in Fig. 5. The body of the blank is formed 'with -spaced extensions 20, which, when brought together and bent, form the sections or parts of the socket 16, as indicated in Fig. 4. v

From thejoregoing deseription,taken inV connection uwith the accompanying drawing, the advantages of the construction and of the method of operation will be're'adily apparent to those skilled in the art to which the invention appertains, and while I have described the principle of operation of the invention, together 4with thedevice which I -now consider to be the embodiment thereof,

I desire to have it understood that the device showr is merely illustrative, and that' such changes may be made when desired as thereof is proi are within the scope of the claims appended hereto.

Having thus described the invention what i `is claimed as new, is 1. In a spark plug for internal combustion engines, the combination 'of' a metal shell, an insulating body secured within the metal within the lower contracted portion ofI the upper enlarged opening, leaving the walls of an axial opening" upper and lower the'latter above the metal socket to form the guard, an electrode located within the lower opening of the body, and a metal connector joining the metal socket and electrode.

'2. ./\.sparkplug for internal combustion engines comprising a metal shell, a body of dielectric material. secured within the metal shell and having its lower portion contracted and its upper endv extended beyond the shell to form a guard, said body having openil'lgs in opposite end portions and a central opening connecting the end openings, 'the upper openinghaving its lower end contracted, a metal socket fitted .within the contracted portion of the 'electrode arranged Iin the lower opening of the body, and connecting means adjustably connecting the metal socket and electrode.

In testimony whereof I affix my signature in presence df two witnesses.

. l H. WILBUR JONES.

Witnesses: l

CHAS. E. LEIGH, R. W. HOGEMAN 

